after a overheating problem at the track, I decided that I needed to address my cooling. Now, the primary reason I overheated was because one of my rad fans decided to melt itself off the motor so I lost my 4-blade fan, but nonetheless, my intake air temps reached 87°C which is WAY too high. Thank god I was injecting 50/50 meth/water, but I still need to address my intake air temps

current setup, the cone intakes are basically sucking up the super hot air coming from behind the radiator, baaaaad



Unfortunately those two cone intakes are bloody massive, so there's not a whole lot of room to build anything there. I had a air pump delete belt lying around from a earlier project that never got started so the airpump went, giving me more room to work with.

So I figure the best way to draw air is similar to the stock airbox mod where you draw air from the side of the radiator, but since my stock airbox is gone, I need to find a way to seal the cones in otherwise air just follows the path of least resistance.

cardboard mock up, it fits!!



so picked up some ductwork sheet metal and went to town. The base plate is actually the side of a old computer case i had lying around, I used that as the base because I wanted something stronger there. And I'm a huge fan of rivets



Next is to build the channel for the air to go up from the side of the radiator, rivet it to the bottom of the case, spraypaint the inside so I know where to cut, remove the channel, and dremel out a slit, then rivet the channel back on. Sorry not a whole lot of in-progress pics, but here's how it looks now







sweet, now I just need to build a lid to seal it from the top, and voila! cold air!

The inner diameter of the intake is 2.4" so the cross sectional area is:

2 x (3.14*(1.2^2) = 9.04 square inches

So I cut the slit to be 9" long and 1" wide just to maintain at least that cross sectional size. Of course, the air is turbulent as heck, but It'll find its way I'm sure.

More pics when I figure out what I'm doing for the lid. Will likely use goop or silicone to seal off all the seams, and might use vacuum hose around all the exposed sharp edges to save my fingers and maybe make a good seal with the lid.

A few other pictures from other angles:

 

looks good. it's like a replica M2 airbox.

 

oh wow you're right! I wonder if I saw that picture before and thats how the idea got into the back of my head ha ha.

Oh well, M2's seems to cost quite a bit more, $10 in sheet metal and some rivets, $50 for the two cone filters, and a bit of elbow grease, I think I'll still be happy with this

The M2's looks like a very slick design though, I would have loved to have that instead but man are they ever expensive...

 

Looks almost like mines execpt its all welded. I also have the slit on the same area. For the top I have two 10mm bolts that hold the lid to the box. You can do that by riveting a small 90 degree bracket and drill/tap so you can lock it down.

For the sharp edges use simple weather strip to seal the box.

 

 

Nice DIY budget build. Get a vented hood and get the hot air out of the engine bay

 

Congrats on your setup. You would be much better off with a modified stock airbox.

A larger intercooler would help a lot with intake temps on the track.

 

"better off with a modified stock airbox" - how so? his airbox looks to function the exact same as your "cheap bastard" modified airbox or the M2 airbox. it draws air from the same point, and i'm sure his filters have greater surface area than a single oem airbox filter.

 

^ perhaps its because you retain that air scoop thing that connects from the intercooler duct. Although if he were to upgrade to certain bigger intercoolers that option would be out anyway

 

The problem with it is the air entry opening. Regardless how much surface area he has with his cone filters, the air still has to travel through the smallish opening 1st. He's not going to get any more performance out of this compared to modifying the stock air box. Also the secondary turbo isn't going to get much air since the primary is going to suck most of the incomming air 1st. The air entry needs to be reloacated and made larger since he's fabing from scratch.

 

That looks NICE! single turbo would have made things easier too since it would have been one filter instead of two

nice intercooler fan! That's one pimp cooling setup

 

thats a lot of work i give u an (A) for effort... but u could have used the adam c airbox mod to the stock air box and had better results plus a better looking engine bay. time wise you would have saved a lot and the end result would have been the same.

but great work anyway

jeff

 

IIRC someone figured out awhile back that its a BAD thing to have the intake box pull air from the IC duct - at full boost the car begins to suck air from the engine bay thru the intercooler, instead of pulling it from the front of the car as it was intended.

 

Given the stock air box has rather good thermal insulating qualities I agree that the op is better off using a modified stock unit. http://www.fd3s.net/intake.html

The downside of the stocker is it's size and thus one must stick to the stock or IC or other small units. So this brings me to this question:

to the OP,

Why the are you still using the stock IC??? You are going through a heck of a lot of trouble in trying to cool air at the intake only to have those gains be negated at the IC.

 

This is exactly correct except that this modification's performance will fall far short of a properly modified stock air box. In addition to the points made above, a properly modified box has 2 openings for a much greater air supply.

 

I think your best bet would be a stock box modified and add a good A/I kit leaving the stock intercooler in place . this will cool intake temps down a great deal allowing the best of both worlds more air in the box and cooler temps because of the A/I . with the use of A/I or meth there is no need to replace the stock intercooler anymore at least I don't think so.



jeff

 

you still didn't address what i said:

and yes, i understand that the 'cheap bastard' box has 2 openings (one like the m2, one to the ic duct) but still unless i see some legit flow testing how do i know that this paradox is remedied by adding the second opening? for all you know, the 'cheap bastard' mod could be pulling air though the ic from the engine bay still.

 

I thought I had answered your question. I have had several people try my airbox mod with the stock duct blocked off. Once they "saw the light" and put the stock duct back on, all realized an immediate noticeable performance gain. I think some of the ones that did this posted in my "Cheap Stock Airbox" mod thread.

While there my be some air pulling back thru the intercooler at low speeds (with my mod). The effect is minimal. At higher speeds it won't happen at all due to pressure from the force of air entering the front opening, and less air being pulled into the intake from the front due to the new underside opening. My mod reduces or eliminates air being pulled back thru the intercooler.

I truly hope I have explained it better this time.

 

so the reason I'm not doing the stock airbox mod is simply because I no longer have my stock airbox.

Why I don't get a bigger intercooler? because 1) I'm too cheap, and 2) I like the fact that the stock intercooler flows air amazingly (according to autospeed http://www.autospeed.com/A_1931/cms/article.html)

Lastly I am running meth injection which reduces my need for a large intercooler.

anyways, I made a lid last night, overall this project costed me 2 sheets of sheet metal, about $4.57cad each.



I just used 2 rivets to hold the lid on, when it comes time to change my filters I'll just drill out the two rivets, change the filters, then rivet them back on.

 

$4.57 man u still have enough money to buy DEI heat tape and do the whole box and still keep you custom box under $30

KUDOS from me bro!

 

Looks good. I would be interested in hearing the temperature difference you notice.

theorie, can you find the thread that shows that if you bring air from the duct you can suck air back through the IC?

The reason I ask is because I did something like this to my IC.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/stock-intercooler-fix-901311/

Simply doing this reduced my intake temps by an addition 10 degrees. Obviously this was a result of increased air flow. If I am pumping more air through the duct, I might be able to draw air from the duct like this.....

 

looking for the original info, but heres another thread where someone was talking about it:

i mean just look at the intercooler duct: the opening at the front is like 1" high x 10" wide, meanwhile on the IC side its like 8x the size. it seems to be like it would he a hell of a lot easier for air to flow from the engine bay backwards thru the IC and into the intake at WOT. now if i can just find the thread where the original data came from...

---edit---

found more info:

so like i said - it's better to have an intake duct that is NOT connected to the IC duct.

if it happens on the stock twins, i can image it would be even WORSE with an aftermarket single

 

Gotcha.

But IMO the stock unit sucks ***. When I replaced my stocker with a PFS units I got an extra 2 lbs of boost (less pressure drop) and my intake temps hovered in the low 40's (prior they were in the 60's). Now I have a large SMIC and my temps are in the low 30's (but I'm single too now so it doesn't mean much in terms of comparing between the two).

Agreed.

Great fab work and I love threads like this. I know that in close to stock setups ducting cool air does make a difference, but I'm not sure if the same applies if you have A.I. Get back to us and tell us if it made a difference.

 

also remember that part of the reason why people replace the stock IC is because the plastic end tanks tend crack/split, resulting in boost leak. remember, they're made out of ~20 year-old abs plastic and have been subjected to the occasional 10psi of pressure since the car rolled off the lot.

 

Here's a lesson for most people. How many engines has everyone seen with a missing battery cover or the entire enclosure gone? Well if you remember another thread where someone removed the lead acid battery that was not covered and acid ate the metal underneath. The battery is supposed to be enclosed and it is cooled via the SMIC ducting.

Now if you notice not only did he cover the top hole, he also covered the side hole which is used to vent the battery box. He is also using a sealed battery that won't leak acid.